Tomography allows the determination of a three-dimensional function from two-dimensional data. Originally driven to provide for non-invasive techniques to peer inside the human body, the development and application of tomography has had a significant impact on a wide range of disciplines, from medical diagnosis to oceanography and seismology. Conventional tomographic techniques yield three-dimensional structural or chemical information with macroscopic resolution, while recent advances in electron microscopy have allowed nanoscale reconstruction of material geometries.
Still, optical tomography with sub-wavelength, nanometer-scale resolution remains a significant challenge. Capturing the often complex three-dimensional nature of light-matter interactions with nanometer-scale spatial and spectral resolution remains a significant challenge.